Re: [PATCH v2] mmc: sdhci: add quirk for ACMD23 broken

[Scott Branden <sbranden@broadcom.com>]

Hi Chris,

We'll finish off cleaning up our driver that uses this patch for review 
then.

Thanks,
  Scott

On 14-12-17 11:48 AM, Chris Ball wrote:
> Hi Scott, sorry for the delay,
>
> On Fri, Dec 05 2014, Scott Branden wrote:
>> Add quirk to handle broken auto-CMD23.
>> Some controllers do not respond after the first auto-CMD23 is issued.
>>
>> This allows CMD23 to still work (mandatory for the faster UHS-I mode)
>> rather than disabling CMD23 entirely via SDHCI_QUIRK2_HOST_NO_CMD23.
>>
>> Signed-off by: Corneliu Doban <cdoban@broadcom.com>
>> Signed-off-by: Scott Branden <sbranden@broadcom.com>
>> ---
>>   drivers/mmc/host/sdhci.c  | 3 ++-
>>   include/linux/mmc/sdhci.h | 2 ++
>>   2 files changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index ada1a3e..b37331f 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -2985,7 +2985,8 @@ int sdhci_add_host(struct sdhci_host *host)
>>   	/* Auto-CMD23 stuff only works in ADMA or PIO. */
>>   	if ((host->version >= SDHCI_SPEC_300) &&
>>   	    ((host->flags & SDHCI_USE_ADMA) ||
>> -	     !(host->flags & SDHCI_USE_SDMA))) {
>> +	     !(host->flags & SDHCI_USE_SDMA)) &&
>> +	     !(host->quirks2 & SDHCI_QUIRK2_ACMD23_BROKEN)) {
>>   		host->flags |= SDHCI_AUTO_CMD23;
>>   		DBG("%s: Auto-CMD23 available\n", mmc_hostname(mmc));
>>   	} else {
>> diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
>> index dba793e..d979cf9 100644
>> --- a/include/linux/mmc/sdhci.h
>> +++ b/include/linux/mmc/sdhci.h
>> @@ -100,6 +100,8 @@ struct sdhci_host {
>>   #define SDHCI_QUIRK2_BROKEN_DDR50			(1<<7)
>>   /* Stop command (CMD12) can set Transfer Complete when not using MMC_RSP_BUSY */
>>   #define SDHCI_QUIRK2_STOP_WITH_TC			(1<<8)
>> +/* Controller broken with using ACMD23 */
>> +#define SDHCI_QUIRK2_ACMD23_BROKEN			(1<<9)
>>
>>   	int irq;		/* Device IRQ */
>>   	void __iomem *ioaddr;	/* Mapped address */
>
> This patch doesn't apply the quirk to any chipsets, so the patch
> doesn't actually change any behavior when run on a mainline kernel.
> Do you have a patch to apply the quirk to your chipset too?  We don't
> typically accept patches that "don't do anything" for mainline users,
> so that's why we'd like to see the chipset patch too.
>
> Thanks,
>
> - Chris.
>